Insulate ductwork. Ensure that ducts throughout the system are sealed and insulated—up to 30 to 40 percent of your cooling energy can be lost through leaks or heat when uninsulated ducts pass through uncooled spaces like attics and garages.
Perform seasonal checks. During the season, keep vegetation at least two feet away from the unit. Clean the grills and filter(s) monthly and replace the latter as needed. Clear debris and dirt from condenser coils and check for blockages in the pipe that drains condensed water from the indoor unit.
Use a programmable thermostat. Proper use of a programmable thermostat can reduce your cooling costs by up to 20 percent. Also consider adding a ceiling fan, which will allow you to set your thermostat to a higher temperature. And find more ways to cut your cooling costs.